In our new study Directors: Older and Wiser, or Too Old to Govern?, we investigate this boardroom aging phenomenon and examine how it affects board effectiveness in terms of firm decision making and shareholder value creation. On the one hand, older independent directors can be valuable resources to firms given their wealth of business experience and professional connections accumulated over the course of their long careers. Moreover, since they are most likely to have retired from their full-time jobs, they should have more time available to devote to their board responsibilities. On the other hand, older independent directors can face declining energy, physical strength, and mental acumen, which can undermine their monitoring and advisory functions. They can also have less incentive to build and maintain their reputation in the director labor market, given their dwindling future directorship opportunities and shorter expected board tenure as they approach normal retirement age.

The past two decades have witnessed dramatic changes to the boards of directors of U.S. public corporations. Several recent governance reforms (the 2002 Sarbanes-Oxley Act, the revised 2003 NYSE/Nasdaq listing rules, and the 2010 Dodd-Frank Act) combined with a rise in shareholder activism have enhanced director qualifications and independence and made boards more accountable. These regulatory changes have significantly increased the responsibilities and liabilities of outside directors. Many firms have also placed limits on how many boards a director can sit on. This changing environment has reduced the ability and incentives of active senior corporate executives to serve on outside boards. Faced with this reduced supply of qualified independent directors and the increased demand for them, firms are increasingly relying on older director candidates. As a result, in recent years the boards of U.S. public corporations have become notably older in age. For example, over the period of 1998 to 2014, the median age of independent directors at large U.S. firms rose from 60 to 64, and the percentage of firms with a majority of independent directors age 65 or above nearly doubled from 26% to 50%.

In our new study Directors: Older and Wiser, or Too Old to Govern?, we investigate this boardroom aging phenomenon and examine how it affects board effectiveness in terms of firm decision making and shareholder value creation. On the one hand, older independent directors can be valuable resources to firms given their wealth of business experience and professional connections accumulated over the course of their long careers. Moreover, since they are most likely to have retired from their full-time jobs, they should have more time available to devote to their board responsibilities. On the other hand, older independent directors can face declining energy, physical strength, and mental acumen, which can undermine their monitoring and advisory functions. They can also have less incentive to build and maintain their reputation in the director labor market, given their dwindling future directorship opportunities and shorter expected board tenure as they approach normal retirement age.

We analyze a sample of S&P 1500 firms over the 1998-2014 period and define an independent director as an “older independent director” (OID) if he or she is at least 65 years old. We begin by evaluating individual director performance by comparing board meeting attendance records and major board committee responsibilities of older versus younger directors. Controlling for a battery of director and firm characteristics as well as director, year, and industry fixed effects, we find that OIDs exhibit poorer board attendance records and are less likely to serve as the chair or a member of an important board committee. These results suggest that OIDs either are less able or have weaker incentives to fulfill their board duties.

We next examine major corporate policies and find a large body of evidence consistently pointing to monitoring deficiencies of OIDs. To measure the extent of boardroom aging, we construct a variable, OID %, as the fraction of all independent directors who are categorized as OIDs. As the percentage of OIDs on corporate boards rises, excess CEO compensation increases. This relationship is mainly driven by the cash component of CEO compensation. A greater OID presence on corporate boards is also associated with firms having lower financial reporting quality, poorer acquisition profitability measured by announcement returns, less generous payout polices, and lower CEO turnover-to-performance sensitivity. Moreover, we find that firm performance, measured either by a firm’s return on assets or its Tobin’s Q, is significantly lower when firms have a greater fraction of OIDs on their boards. These results collectively support the conclusion that OIDs suffer from monitoring deficiencies that impair the board’s effectiveness in providing management oversight.

We employ a number of approaches to address the endogeneity issue. First, we include firm-fixed effects wherever applicable to control for unobservable time-invariant firm-specific factors that may correlate with both the presence of OIDs and the firm outcome variables that we study. Second, we employ an instrumental variable regression approach where we instrument for the presence of OIDs on a firm’s board with a measure capturing the local supply of older director candidates in the firm’s headquarters state. We find that all of our firm-level results continue to hold under a two-stage IV regression framework. Third, we exploit a regulatory shock to firms’ board composition. The NYSE and Nasdaq issued new listing standards in 2003 following the passage of the Sarbanes-Oxley Act (SOX), which required listed firms to have a majority of independent directors on the board. We show that firms non-compliant with the new rule experienced a significantly larger increase in the percentage of OIDs over the 2000-2005 period compared to compliant firms. A major reason for this difference is that noncompliant firms needed to hire more OIDs to comply with the new listing standards. Using a firm’s noncompliance status as an instrument for the change in the board’s OID percentage, we find that firm performance deteriorates as noncompliant firms increase OIDs on their boards. We also conduct two event studies, one on OID appointment announcements and the other on the announcements of firm policy changes that increase the mandatory retirement age of outside directors. We find that shareholders react negatively to both announcements.

In our final set of analysis, we explore cross-sectional variations in the relation between OIDs and firm performance and policies. We find that the negative relation between OIDs and firm performance is more pronounced when OIDs hold multiple outside board seats. This evidence suggests that “busyness” exacerbates the monitoring deficiency of OIDs. We also find that for firms with high advisory needs, the relation between OIDs and firm performance is no longer significantly negative and in some cases, becomes positive. These results are consistent with OIDs using their experience and resources to provide valuable counsel to senior managers in need of board advice. Also consistent with OIDs performing a valuable advisory function, our analysis of acquirer returns shows that the negative relation between OIDs and acquirer returns is limited to OIDs who have neither prior acquisition experience, nor experience in the target industry. For OIDs with either type of experience, their marginal effect on acquirer returns is non-negative, and sometimes significantly positive.

Our research is the first investigation of the pervasive and growing phenomenon of boardroom aging at large U.S. corporations and its impact on board effectiveness and firm performance. As the debate over director age limits continues in the news media and among activist shareholders and regulators, our findings on the costs and benefits associated with OIDs can provide important and timely policy guidance. For companies considering lifting or waiving mandatory director retirement age requirements, so as to lower the burden of recruiting and retaining experienced independent directors, our evidence should give them pause. Similarly, while recent corporate governance reforms and the rise in shareholder activism have made boards, and especially independent directors, more accountable for managerial decisions and firm performance, they may also have created the unintended consequence of shrinking the supply of potential independent directors who are younger active executives. This result has led firms to tap deeper into the pool of older director candidates, which our analysis shows can undermine the very objectives that corporate governance reforms seek to accomplish.

*Ronald Masulis is Scientia Professor of Finance at University of New South Wales Australian School of Business; Cong Wang is Professor of Finance at The Chinese University of Hong Kong, Shenzhen and the associate director of Shenzhen Finance Institute; Fei Xie is Associate Professor of Finance at the University of Delaware; and Shuran Zhang is Associate Professor of Finance at Jinan University. This post is based on their recent paper.